calculate_cost

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, so the description carries the full behavioral burden. 'Calcula' implies a side-effect-free computation, but nothing states that this is read-only, whether the result is deterministic, whether antecipation changes the output, or what fees the 'custo real' includes.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

A single front-loaded sentence with no filler; the verb and the resource lead. It is appropriately sized for a simple two-required-parameter calculation tool.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description should at least characterize the return value, but 'custo mensal real' leaves open whether the result is a single number, a breakdown, or a comparison. For a low-complexity calculator it is minimally adequate but leaves the return shape unspecified.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% with two fully documented enums, so the schema already explains brand and tier. The description's only added nuance is 'perfil específico' (mapping to tier) and the implication that antecipation affects the cost, which is marginal beyond the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb (calcula) and resource (custo mensal real de uma maquininha) scoped to a specific profile, so an agent understands it produces a single-brand cost figure. It is clearly distinct from compare_brands in intent, though it never names the siblings to reinforce that distinction.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

There is no explicit when-to-use guidance, no mention of prerequisites (e.g. that brand/tier must come from get_brands/get_tiers), and no statement of when to prefer compare_brands instead. The agent must infer the routing from the name alone.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.